Maybe he'd like to get to know you better, but he's shy and unsure what to say in an actual message. Or, he might be the kind of guy who winks at a lot of woman and can't be bothered sending a message. If this is the case, it doesn't mean much.
The law of conservation of mass (from Lavoisier) states that mass can be neither created nor destroyed (but it may change its form into something that is not desired, such as heat with an engine) or that in a chemical reaction, the total mass of the reacting substances is equal to the total mass of products formed.
The Law of Conservation of Mass. The Law of Conservation of Mass dates from Antoine Lavoisier's 1789 discovery that mass is neither created nor destroyed in chemical reactions. In other words, the mass of any one element at the beginning of a reaction will equal the mass of that element at the end of the reaction. If we account for all reactants and products in a chemical reaction, the total mass will be the same at any point in time in any closed system.